My uncle did that with his car after he put the cam in it I walked up and asked him what he was doing kneeled down behind his car as it ran. He doesn't huff so I knew that wasn't it he just held his hand up to me to be quiet and said "Shhhh... it talking to me... listen..." The idle changed a bit and got just a little rough and he said "There! Ya hear it? Its talkin.."